math
posted by lindsay on .
Solve the equation 8 cos^2 X 2 =0 given that 180< or equal to X <or equal to 360 degrees.

8cos^2X  2 = 0
8cos^2x = 2
cos^2x = 2/8 = 0.25
cosx = sqrt(0.25) = 0.5
Xr = 60o = Reference angle.
XXr = 180
x60 = 180
X = 180+60 = 240o.